Andreas Vesalius (1515–1564) was a Flemish physician who revolutionized the practice of anatomy and changed the way people thought about the human body. Born into a family of physicians and pharmacists, Vesalius began practicing medicine at a time when the approach to the human body was based on ancient knowledge passed down from Galen, a physician who combined the practice of dissection with his knowledge of Greek philosophers (including Aristotle) to explain the structure of the human body and how it worked. Advanced for his own time, Galen came to be regarded as such an authority on the human body that his work later became the basis for medical training; by the Middle Ages in Europe, there was no requirement to learn from real bodies, as it was thought that everything that needed to be known could be found in Galen’s writing.
Vesalius initially trained in the University of Paris (leaving in 1533), where he was taught within an academic school that held the teaching of Galen in the highest esteem. However, in 1537 he moved to the University of Padua and there, while lecturing to medical students, he began dissecting corpses (usually executed criminals). This practice led him to radically re-appraise his entire understanding of the human body and how it works.
Vesalius began to draw diagrams of the anatomy of the bodies he was dissecting. The illustrations were initially undertaken to help in his teaching, but as he drew he gradually began to notice occasional mistakes in Galen’s work (for example, Galen said that the human breastbone was made of seven fragments, when actually it is only three). Vesalius began to suspect a deep and underlying mistake in Galen’s work, eventually figuring out that Galen had never dissected a human, but had limited his dissecting practice to animals (because Roman social norms would not have permitted human dissection).
Beginning at the age of 25, Vesalius set out to prove where Galen had made mistakes, using skeletons of humans and Barbary macaques during his lectures to demonstrate anatomical differences. He also began to compile his series of anatomy illustrations, collecting them into a book that was eventually published in 1543, when Galen was 28 years of age. This book, known as De humani corporis fabrica septem (“Fabrica” for short), is translated as “The Seven Books on the Structure of the Human Body.” In this work he combined detailed writing about the body, careful illustrations of anatomy, and all the latest technological advantages in publishing that the period had to offer.
Reaction to the book was both positive and negative. Many of his old teachers criticized Vesalius for his rejection of Galen, and Vesalius certainly challenged the orthodox dogma in the study of the human body. However, despite the criticism, his work had many supporters. In 1555 a second edition of the “Fabrica” was published. This included some improvements that were a direct result of Vesalius’s increased anatomical experience, gained in the intervening decade or so.
As a result of his work on the “Fabrica,” Vesalius advocated that medical students should learn from dissecting real human bodies, and not animals, as human anatomy could be significantly different from that of other mammals. This led to the foundations of the discipline of comparative anatomy, where researchers study the anatomy of different animals and investigate their similarities and differences. Vesalius’s suggestion that every student needed to learn from hands-on experience of dissection, and not merely from books and illustrations, was a revolutionary new approach to the study of the body. It began a new tradition of anatomical discovery in Europe, where practitioners began to explore the human body in more detail, and trusted in their own observations of phenomena rather than in textbooks.
